Motor bicycle



Feb. Z5, E3.

o. EVINRUDE MOT-OR BICYCLE Filed Dec. 26, 1933 3 Sheets-Sheet l nventor M-mww 9 f attorneys Feb. 25, 1936. o. EVINRUDEv y 2,031,881

MOTOR BICYCLE Filed Dec. 26, 1933 3 Sheets-Sheetl 2 Q@ wks@ (Ittornegg O. EVINRUDE MOTOR BICYCLE 5 Sheets-Sheet 5 Filed Dec. 26, 1933 m n e n Patented Feb..y 25, 1936 UNiTEo STATES PATENT `OFFICE 2.031.881 Moron Brcrcu:

Ole Evinrude, Mlwaukeefwis., assigner yto Outboard Motors Corporation, Milwaukee, Wis., a corporation of Michigan Application December ze, 1988, serai No. 803,955 .11 claims. (ci. 18o-83) More specifically, it is' my purpose to provide a bicycle motor in which the assembly is substantially balanced as to weight, the cylinder, crank case and muiiler assembly being on one side of the bicycle wheel and the engine, fly-wheel and magneto on the other, with the driving roller or pulley between the y-wheel and the crank case in a position to engage the bicycle tire, the parts being distributed symmetrically as to size and weight. i

With particular reference to the engine, it is an object of the invention to provide means in a twocycle enginefor preventing the transfer of 4 lubricating oil from the crank case to the cylinder,

to ensure a more effective lubrication of the crank case parts, and to reduce the amount of oil required.

Other objects, with particular reference to the compact and convenient organization of the structure, will appear from the following disclosure.

En the drawings:

Figure 1 is a view in side elevation showing a fragmentary portion of a bicycle and illustrating the application thereto of a bicycle motor embodying the present invention.

Figure 2 is a detail View of the engine assembly :i5 of my improved device as viewed in the plane indicated at 2-2 in Figure 3.

Figure 3 is a view in transverse section showing my device in the plane indicated at 3 3 in Figure 2.

40 Figure 4 is a fragmentary detail in perspective showing the mounting by-Which thedevice is applied to a conventional bicycle frame.

' Figure 5 is a fragmentary sectional View taken in the plane indicated by the line 5-5 in Fig- "45 ure 3. Like parts are identified by the same reference characters throughout the several Views.

The mounting for my device is an important factor contributing to its successful. installation so on a conventional bicycle. It replaces a section 'ofthe conventional mudguard 9 for the rear bicycle tire 8. A casting I0 provides a short length of substitute mudguard terminating at one end in a. plate II adapted to abut the rear 55 fork I2 of the bicycle and comprising one inember of a clamp to engage said fork. Held to the plate I I by means of a bolt I3 is a complementary clamping plate I 4 which engages the inside of the fork, whereby rigidly to support the substituted mudgard section I0 from the bicycle frame 5 I5. At its rear end the substituted mudguard section Ill terminates in a bracket having ears I6 to receive a. pintle bolt 20 and shouldered for connection with braces 2i which are engaged over the rear axle 22 of the bicycle. 10

The entire motor assembly is fulcrumed on the pintle 20 for the pivotal adjustment which brings the driving pulley or roller to and from engagement with the tire B of the rear wheel, as will hereinafter be described. 15 v The engine and driving parts are assembled upon a frame which includes the crank case 25 and the arm 2B which projects forwardly therefrom and is apertured at 2l to receive the pintle bolt 2G. 2g

Upon this crank case frame is mounted a conventional two cycle engine cylinder 23 within which a piston 29 is reciprocably connected by rod 3B with the crank shaft 3l.

Mounted on the crank shaft 3i is a rotary valve 25 i, best shown in Fig. 2. This valve controls the ignition of the charge from passage 33 to the crank case. The passage 33 extends part way around bushing 36 which provides a suitable bearing in the crank case for the crank shaft 3 i l 3o The charge or mixture is made up as follows.

A tankv 35 is carried on brackets 35 and 3i and v connected by a pipe 38 with carburetor 39. The

rear passage ill through the carburetor is controlled by a throttle valve di and leads to the 35 y passage 33 which has valve controlled communication with the crank case as above described.

The crank case is preferably lubricated by mix- -ing o il with the gasoline in tank 35.

In accordance with conventional practice in 40 two cycle engines, the mixture compressed below the piston in the crank case is transferred to the combustion chamber in cylinder 28 through a transfer passage d5 formedv partly in the crank case casting and partly in the cylinder casting and having its delivery end arranged to be unl covered by the piston in the position in which the parts are shown in Fig. 2.v The communication of this passage with the crank case is novel, however, and is so designed as to minil opening into chamber d6 leading to the transfer passage ld. The rotation of the crank shaft' and crank pin tends to keep all of the iluids in the crank casein rotation at a relatively high speed. The fuel particles are quite largely atomized or vaporized and hence reduced to very small size and weight.` Ilhe lubricating oil, however, is not capable oi so high a degree of atomization and tends to accumulate in a heavier mist or in the form of small globules. The rotating :fluids-in the crank case constitute a very eil'ective means for centr'ifugally separating the heavier particles of oil' from the lighter particles of combustible mixture, since the discharge port 5 leading to the transferpassage is at thecenter of the crank case and can only receive the relatively lighter weight materials therefrom. The lubricating oil will remain in the crank case to a far greater degree than it has been possible to achieve in previous designs of'two cycle engines.

The muier playsy an important part in the design of this device. The exhaust gases pass through the port 8 into the muiercasting i9 v which is of suicient size to assure.' thorough expansion and consequent elimination of noise. The casting extends about the crank case in spaced relation thereto, but is rigidly connected with4 the crank case or frame 25 of the device by bolts at dil. Below the crankcase there is a large chamber 5i closed at its bottom by a foraminous plate 52 providing an outletntting at 53.

The adjustment of the entire assembly upon the bracket l@ is provided by means of a hand lever 55 held in a socket 56 formed on the muiier' casting iid, the motion being transmitted through the mumer to the rest of the assembly.

The operation of the hand-lever will be described later. When the apparatus is in the positiorr shown inthe drawings, the driving roller or pulley 5d mountedl on the crank shaft engages the tire t of the rear wheel of the bicycle with sufficient pressure to ensure an operative driving friction so that in the rotation of the crank shaft motion is transmitted directly to the tire from the pulley or roller 58.

Beyond the roller or pulley is the timer plate 59 of a. 4conventional iiy-wheel magneto. This plate is mounted by means of anti-friction bearings directly upon the crank shaft so as to bev positioned thereby and to partake of any movements of the crank shaft which may occur due nets ed.

The output of the magneto and breaker mechanlsm is delivered' by a, wire 55 to the conventional spark plug 66. yThe operator is protected from accidental contact with this plug by means of a strap 6l which also constitutes a brace for holding the fuel tank 35 rigidly from the muiiler lcasting lig which, as above noted, is solidly conrfiiected with the crank case or frame of the de- It will be noted from an inspection of Fig. 3 that the device is balanced symmetrically with reference to the rear tire. 'Ihe relatively heavy ily-wheel magneto which is mounted on the crank shaft at one side of the driving roller 58 is op- Y acercar posed by the engine cylinder, crank case, and muiier, at the other side of the driving roller. When the device is in use its entire actual weight is sustained on the tire.

The controls permit theentire apparatus to be lifted from the tire either for idling or for the use of the bicycle independently of. the driving mechanism. Bolted to the side Vof the bracket clamp plate il is a strap S9 constituting a guide for the adjusting lever 55. An. extension 'l0 on this strap may be engaged in either of two positions by a paWl ll biased byv spring i2 and released by a hand grip i3. When the notch in the pawl is engaged' with the extension lil as shown in Fig. 1, the driving roller 58 will be clamped tightly upon the tire, as shown in Fig. 3. It it be desired to lift the motor assembly to free the rollerof contact with the tire, the grip i3 will operate it to release pawl li from extension lil. The hand lever 55 is then depressed to oscillate the entire bicycle motor about the fulcrum pintle 20 to a position in which the roller clears the tire and the extreme end of the pawl is then engaged beneath the extension of plate 69, thereby supporting the bicycle motor in an elevating position with respect to the tire.

The other controls include a Bowden wire 'ifi I leading to the handle bars where any conventional means of operation may be provided for the manipulation of the throttle Valve di, and a secengine.

It willl be noted that the forward portion of lmudguard 9 remains secured to the rear fork i2 of the bicycle, and means is provided at 8f3 for supporting from the engine the front end of the rear portion of mudguard 9. Thus, the entire assembly is conveniently and expeditiously applicable to a conventional bicycle structure with very little change, and may be used or not under the complete control of the operator to provide a simple, compact, symmetrical and balanced means of bicycle propulsion by power.

I claim:

1. A bicycle motor mounting comprising the combination with a bicycle having a rear fork and a mudguard element spaced rearwardly from said fork, of a bracket member including a mudguard shaped portion and provided with a clamp engaged with said rear fork, said member projecting rearwardly from the clamp, brace means supporting said bracket member from another point on` said fork, a motor frame element pivoted to said bracket member, and means connecting said motor frame element and mudguard.

2.-*A bicycle motor mounting comprising the combination with a bicycle fork having legs spaced to receive a wheel, of plates applied in clamping relation to said forkfa channel bracket member extending rearwardly from one of said plates about the Wheel as a partial mudguard, and a. bicycle motorv frame pivoted to said member.

3. A device of the'character described, comprising the combination with a bicycle frame engaging clamp, of a bracket carried thereby and projecting rearwardly therefrom, propulsion means pivoted upon said bracket, a lever connected with vsaid propulsion means and projecting forwardly of said bracket, and a latch and latch keeper connected between said bracket and leverand res,os1,se1 w 3 leasably engaged with each other to fix said lever in either of two predetermined positions affect'- ing the pivotal adjustment of said propulsion means with respectl to said bracket.

5 4. In a device of the character described, the .combination with a driving means, of an engine at one side thereof having a crank shaft upon which said means is mounted, a y-wheel at the other side of saidmeans upon said crank shaft` and including magneto means for supplying said engine with ignition current, exhaust means extending about one side of said crank case to a point therebeneath, and charge forming means at the other side of said crank case.

5. In a device. of the character described, the combination with a driving means, of an engine at one side thereof having a crank shaft upon which said means is mounted, a y-wheel at the other side of said meansupon said crank shaft and including magneto means for supplying said engine with ignition current, exhaust means extending about one side of said crank case to a point therebeneath, and charge forming means at the other side of said crank case, together with a 25 fuel tank connected with said charge forming .means and positioned lthereabove substantially paralleling said crank shaft, and a brace extending across said engine from said fuel tank to said exhaust means.

6. In a device of the character described, the combination with a bracket, of propulsion means including a crank case provided with a forwardly extending arm pivoted to said bracket, said arm comprising a frame upon which the propulsion means is adjustable about said pivot, a cylinder and crank shaft operatively associated with said crank case, and an exhaust means connected with said cylinder and extending about said crank case to a point therebeneath, said exhaust means having a member providing a rigid connection between it and said crank case.

7. In a device of the character described, the combination with a bracket, of a crank case provided with a forwardly extending arm pivoted to said bracket and comprising a frame for the adjustment of propulsion means, a cylinder and crank shaft operatively associated with said crank case, and an exhaust means connected with said cylinderv and extending about said crank case to a point therebeneath, said exhaust means having a 8. A mounting for attaching a bicycle motorto a bicycle having a rear fork with spaced leg porthereof, and fulcrum means at the rear end of said bracket arranged to receive said motor.

9. In a bicycle and motor assembly, the combination with a rear bicycle fork having spaced legs and a wheel operable between the legs of 10 said fork, of a clamp applied to the legs of said fork spanning said space above the position of the wheel therein, a bracket member carried on said clamp and projecting rearwardly therefrom about the wheel as a guard, and a bicycle motor having 15 a portion fulcrumed to said member and operatively connected in potential driving relation to said wheel.

10. A device of the character described, comprising the combination with clamping members 20 applicable to the rear fork oi a bicycle, of a bracket projecting rearwardly therefrom, a propelling device comprising a frame pivoted tothe bracket, an engine cylinder on the frame, an engine driven driving roller engageable and disen- 25 gageable with a bicycle wheel upon the pivotal movement of said frame, exhaust means connected with the cylinder, and a lever rigidly connected with the exhaust means and projecting forwardly beyond said bracket, said lever being 30 of a length such that its end will be available for manipulation in front of the rider of a bicycle towhich said bracket is applied for adjusting said frame and device about said pivotal connection with said bracket. 35

11. A motor bicycle, comprising a bracket, an engine structure including a drive roller and pivotally connected with the bracket to receive support therefrom, a mounting clamp for connecting said bracket with a.bicyc1e frame in 40 a position such that said roller is engageable with and disengageable from a bicycle wheel upon the pivotal movement of said engine with respect to said bracket, a lever connected with said engine and projecting across and beyond said bracket 45 to a position within easy reach of the operator, detent means engageable betweensaid lever and bracket to x the pivotal position-of said engine and operatively arranged for manipulation by the operator in his manipulation of said lever, and 50 an engine control extending from said engine to said lever and connected therewith to partake of the movement thereof whereby to be accessible to the operator inl altpositions of said lever independently of any extraneous connections to the bicycle.

` OLE EVINRUDE. 

